Nagios Introduction

Nagios is a free, open-source web-based network monitor developed by Ethan Galstead. Nagios is designed to run on Linux, but can be also be used on Unix variants. Nagios monitors the status of host systems and network services and notifies the user of problems.

Nagios Functionality

In common with many open source utilities, installation requires a degree of system administrator experience. Nagios is definitely not for the novice, unless you are prepared to put the effort in learning the basics. But with a wide range of features, including a number of web interfaces, Nagios is a very useful, feature rich monitoring tool.

A large number of plug-ins available from the Nagios Library, means you can design its capabilities to your own requirements. Amongst others, Nagios monitors services such as SMTP, POP3, HTTP, PING and resources such as disk and memory usage, log files, processor load and so on and integrates with the Sensatronics IT Temperature Monitor to allow monitoring and alerting of server room and device temperature to your own parameters.

Nagios will also allow scheduling so that for instance if you planned network outage you can suppress host and service notifications. Nagios also allows users the flexibility to develop custom host and service checks. All the plug-ins are available for download from the Nagios library. It is also possible to set up a hierarchy of alerts for instance if alerts are not responded to.

How does Nagios work?

The monitoring daemon runs intermittent checks on hosts and services you specify using external "plugins" which return status information to Nagios. When problems occur Nagios alerts you via email, instant message, SMS. Current status information, historical logs, and reports can all be accessed via a web browser.

Supported Nagios Platforms

Nagios runs on Linux and Unix variants. Nagios does not support Microsoft Windows.

Nagios License

Nagios is licensed under the GNU (General Public Licence) which means that it is free for your own use and you may copy, distribute and/or modify Nagios.

Nagios Support

As with other open source projects, support is available and given freely by developers and users via mailing lists, forums and FAQs. In addition, there are a number of companies who offer consulting and support contracts for Nagios.

Conclusion

If you have the skill and the time to install Nagios and get it up and running, it offers excellent value (ie for nothing) and functionality perfect for the small to medium enterprise that would balk at the cost of traditional monitoring systems.

See Also

Sensatronics E4 Nagios Temperature Monitor
Sensatronics EM1 Nagios Temperature/Humidity/Wetness Monitor

About the Author

Annie Raynor Annie Raynor, Bsc(Hons), possesses extensive experience in IT marketing and PR, particularly in the field of network management. In 2003 she joined OPENXTRA as Marketing and Business Development Manager, part of her remit being to raise OPENXTRA’s profile and assist in its growth.